Intermediate hardness of materials
Intermediate hardness
The table below incorporates additional substances that may fall between levels:
|
Hardness
|
Substance or mineral
|
|
0.2–0.3
|
caesium, rubidium
|
|
0.5–0.6
|
lithium, sodium, potassium
|
|
1
|
talc
|
|
1.5
|
gallium, strontium, indium, tin, barium, thallium, lead, graphite
|
|
2
|
hexagonal boron nitride, calcium, selenium, cadmium, sulfur, tellurium, bismuth
|
|
2.5 to 3
|
magnesium, gold, silver, aluminium, zinc, lanthanum, cerium, Jet_(lignite) (lignite)
|
|
3
|
calcite, copper, arsenic, antimony, thorium, dentin
|
|
4
|
fluorite, iron, nickel
|
|
4 to 4.5
|
platinum, steel
|
|
5
|
apatite, cobalt, zirconium, palladium, tooth enamel, obsidian (volcanic glass)
|
|
5.5
|
beryllium, molybdenum, hafnium
|
|
6
|
orthoclase, titanium, manganese, germanium, niobium, rhodium, uranium
|
|
6 to 7
|
glass, fused quartz, iron pyrite, silicon, ruthenium, iridium, tantalum, opal
|
|
7
|
quartz, vanadium, osmium, rhenium
|
|
7.5 to 8
|
hardened steel, tungsten, emerald, spinel
|
|
8
|
topaz, cubic zirconia
|
|
8.5
|
chrysoberyl, chromium, silicon nitride
|
|
9-9.5
|
corundum, silicon carbide (carborundum), tungsten carbide, titanium carbide, stishovite
|
|
9.5–10
|
Rhenium diboride, tantalum carbide, titanium diboride, boron nitride, boron.
|
|
10
|
diamond
|
|
>10
|
nanocrystalline diamond (hyperdiamond, ultrahard fullerite)
|
Clirik Vertical roller mill, HGM micro powder grinding mill, Raymond mill, high pressure suspension grinding mill are the equipments specializing in producing fine and superfine powder of non-inflammable, non-explosive and brittle materials with Mohs’s hardness under six, such as calcite, chalk, limestone, dolomite, kaolin, bentonite, talc, mica, magnesite, illite, pyrophyllite and vermiculite, sepiolite, attapulgite, rectorite, diatomite, barite, gypsum, alunite, graphite, fluorite, rock phosphate, kalium ore, pumice, etc., totally more than 100 kinds of materials.